EARNINGS PER COMMON SHARE AND DIVIDENDS PER SHARE - Dividends Per Share (Details)		2 Months Ended	3 Months Ended
	Mar. 01, 2020 $ / shares	Feb. 29, 2020 $ / shares	Mar. 31, 2020 $ / shares	Mar. 31, 2020 $ / shares
Dividends Payable [Line Items]
Common stock, dividends, per share, declared (in dollars per share)	$ 0.81	$ 0.738
Increase in quarterly dividend per common share (percent)	9.80%
Common shares
Dividends Payable [Line Items]
Common stock, dividends, per share, declared (in dollars per share)			$ 0.81000
Preferred share investment | Preference Shares, Series A
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.34375
Preferred share investment | Preference Shares, Series B
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.21340
Preferred share investment | Preference Shares, Series C
Dividends Payable [Line Items]
Dividend per share (in dollars per share)	$ 0.25458	0.25305	0.25458
Preferred share investment | Preference Shares, Series D
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.27875
Preferred share investment | Preference Shares, Series F
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.29306
Preferred share investment | Preference Shares, Series H
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.27350
Preferred share investment | Preference Shares, Series J
Dividends Payable [Line Items]
Dividend per share (in dollars per share)				$ 0.30540
Preferred share investment | Preference Shares, Series L
Dividends Payable [Line Items]
Dividend per share (in dollars per share)				0.30993
Preferred share investment | Preference Shares, Series N
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.31788
Preferred share investment | Preference Shares, Series P
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.27369
Preferred share investment | Preference Shares, Series R
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.25456
Preferred share investment | Preference Shares, Series 1
Dividends Payable [Line Items]
Dividend per share (in dollars per share)				0.37182
Preferred share investment | Preference Shares, Series 3
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.23356
Preferred share investment | Preference Shares, Series 5
Dividends Payable [Line Items]
Dividend per share (in dollars per share)				$ 0.33596
Preferred share investment | Preference Shares, Series 7
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.27806
Preferred share investment | Preference Shares, Series 9
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.25606
Preferred share investment | Preference Shares, Series 11
Dividends Payable [Line Items]
Dividend per share (in dollars per share)	$ 0.24613	$ 0.275	0.24613
Preferred share investment | Preference Shares, Series 13
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.27500
Preferred share investment | Preference Shares, Series 15
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.27500
Preferred share investment | Preference Shares, Series 17
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			0.32188
Preferred share investment | Preference Shares, Series 19
Dividends Payable [Line Items]
Dividend per share (in dollars per share)			$ 0.30625